The present invention relates to a refrigerator, and more particularly, to a refrigerator comprising a thermosiphon for conveying the heat generated by a compressor to the upper region of the refrigerator.
In recent years, there has been proposed a refrigerator which comprises a thermosiphon formed by sealing an operating liquid into a closed-loop pipe. According to this kind of refrigerator, the thermosiphon conveys the heat generated by a compressor disposed on the bottom of the refrigerator to the upper region of the refrigerator. The heat conveyed is utilized to heat, e.g., an electric appliance receiving box disposed at the upper portion of the rear wall of the refrigerator body, thereby preventing electric appliances from malfunctioning due to waterdrops and cooling the compressor at the same time. Generally, the whole of the pipe which forms the thermosiphon is secured to the rear wall of the refrigerator body by means of an adhesive tape of aluminum foil, for example, and is arranged vertically along the rear wall. The thermosiphon receives the heat generated by the compressor at the lower most portion thereof to produce bubbles in the pipe. Because of the pumping function achieved by the bubbles, the operating fluid is allowed to circulate in the pipe.
However, the refrigerator having the above structure sometimes fails to sufficiently heat the electric appliance receiving box if the ambient temperature is comparatively low. In this case, waterdrops are caused by the cooled air in the refrigerator, and they inevitably attach on the surface of the electric appliances such as a coolant flow control valve and leads. The inventors of the present invention looked into the reason why waterdrops are collected on the electric appliances when the ambient temperature of the refrigerator is comparatively low. As a result, they found the following reason: When the ambient temperature of the refrigerator is low, the temperature of the compressor does not become very high, and accordingly, the number of bubbles generated in the pipe of the thermosiphon is small. In addition, since the advancing portion of the pipe is adhered to the rear wall of the refrigerator body by means of the aluminum foil tape, the quantity of heat radiated at the advancing portion of the pipe is large. In short, when the ambient temperature of the refrigerator is low, the operating fluid existing in the advancing portion of the pipe is cooled more than necessary. In addition, the number of bubbles generated is small. Therefore, the bubbles are liquefied and disappear in the advancing portion of the pipe. For this reason, the operating fluid cannot circulate smoothly, with the result that the quantity of heat radiated at the upper portion of the thermosiphon is small, and the electric appliance receiving box cannot be sufficiently heated.